"Rift-Related Crustal Scale Extensional Fault Timing and Late Cretaceous-Tertiary Reactivation, U.S. Chukchi Shelf, Alaska"

Blake Odom, Thesis 2016

Abstract: The U.S. Chukchi shelf has a complex tectonic history of several crustal rifting events, and has significant hydrocarbon potential. Interpretation of reprocessed industry seismic data; USGS high-resolution uniboom, near surface seismic; USGS shallow cores; and sparse industry well control provide constraints on the lateral extent and timing of these basement faults. This study maps and temporally categorizes 23 crustal scale, northwest striking basement faults in the mid Chukchi platform. Normal reactivation of Carboniferous faulting in the Late Cretaceous and Tertiary is observed on a majority of the faults, favoring Brookian to Tertiary reactivation across the study area. In addition, some of the other faults are identified as being formed entirely during the Late Cretaceous and Tertiary, offsetting all older strata uniformly. Fossilized Carboniferous and Jurassic faulting provide examples of the pre-existing fault geometries that existed before Cretaceous reactivation of some of the faults. While it has been noted that oblique-slip reactivation has occurred on the southern Chukchi platform, this study examines only dip-slip normal crustal faults found in the mid to northern platform. 3-D temporal models of these faults are also utilized to examine relationships between fault activity timing and the spatial extent of faulting on the mid Chukchi platform.

Full thesis available. Contact the Geology Department at 540-458-8800.